org.braiden.fpm2.crypto.PBKDF2FpmKeyGenerator.java Source code

Introduction

Here is the source code for org.braiden.fpm2.crypto.PBKDF2FpmKeyGenerator.java

Source

package org.braiden.fpm2.crypto;

/*
 * Copyright (c) 2010 Braiden Kindt
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 *  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *  OTHER DEALINGS IN THE SOFTWARE.
 *
 */

import java.security.GeneralSecurityException;

import org.apache.commons.lang.StringUtils;

/**
 * Generate a key using PBKDF2 and the provided mac.
 * The default consructur matches FPM's AES rules.
 * But this class should be able to support other
 * hmacs, keylengths, and interations.
 * 
 * @author braiden
 *
 */

public class PBKDF2FpmKeyGenerator implements FpmKeyGenerator {

    public static final int DEFAULT_KEY_LENGTH_BYTES = 32;
    public static final int DEFAULT_ITERATIONS = 8192;
    public static final String DEFAULT_HMAC_ALGORITH = "HMACSHA256";

    private PBKDF2KeyGenerator keyGenerator;

    public PBKDF2FpmKeyGenerator() throws GeneralSecurityException {
        this(DEFAULT_KEY_LENGTH_BYTES, DEFAULT_ITERATIONS, DEFAULT_HMAC_ALGORITH);
    }

    public PBKDF2FpmKeyGenerator(int keyLength, int iterations, String hmac) throws GeneralSecurityException {
        keyGenerator = new PBKDF2KeyGenerator(keyLength, iterations, hmac);
    }

    @Override
    public byte[] generateKey(String secret, String salt) throws GeneralSecurityException {
        byte[] saltBytes = StringUtils.substring(salt, 0, keyGenerator.getKeyLengthBytes() / 2).getBytes();
        return keyGenerator.generateKey(secret, saltBytes);
    }

}